Almost all compressors have 2 cylinders… Stage 1 and stage 2 compression. As for the ‘suffocation’, it just takes a sealed door and venting to the outside… So, door to the kitchen is closed and sealed, airflow is in at the top, past the dry ice and out at the bottom… Damned thing is already against a frickin’ wall… Vent at the top and bottom to outside and it’s done.

I think the algae thing is pretty cool but am always seeking contingency plans which don’t leave me totally dependant on living organisms.

That in mind, there are some interesting technologies available to you. Liquid nitrogen can be manufactured using a heat exchanger(car radiator) to wick heat away from a compressed air cylinder. Repeat expansion and compression of this gas can eventually boot strap it’s way to liquid temperatures. You can blow your cold gas on to the hose/pipe carrying it to the nozzle and you get a regenerative effect where the gases own expansion is pre-cooling the gas in the process of being expanded.

Do a search for “DIY liquid nitrogen” and you’ll get some hits. This same liquid nitrogen can be used to condense pure oxygen through a device that resembles a still. “DIY liquid oxygen”

It stands to reason that you could use these two liquids to cryogenically freeze carbon dioxide out of the air. A cryogenic rebreather.

This of course is all absurdly dangerous, much more so than the risk of suffocation from lack of algae. That said, I’m curious how much Co2 would collect on a car radiator which had liquid nitrogen pumped through it. Would some of this snow actually be oxygen? Could the process be used as a form of fractional crystalation?

How fast would you die from the evaporating nitrogen poisoning your atmosphere?

I was off base here. The Like a Fish technology is pretty cool, and the Algae seems to be proven and cost effective.

How is your aquirium coming elspru? Have you done any testing using CO2 cylinders and oxygen sensors? I hate to say it but pet store rats get fed to snakes all the time. Atleast with your aquarium they have a chance.

You will need light to grow the algie – and you will need a lot of water, say, 1000L of water per person, and anyone knows that humidity will be a issue in a enclosed space and that much water – however for those who are shallow enough to get light, I could see it as a great extender of your air – if your close enough for light, then you can occasionally vent and exchange the air (And you can eat algie). or have enough power to run lights – but if your running lights it may be more effective to do what the space station does and produce O2 from water and then clean out the Co2 and other toxins with filters.

Dehumidifiers might be a good way to get some of the moisture out (and provide drinking water) but that is energy intensive. Activated Carbon is a great air filter to remove toxins from the air – as in a cosed loop you will have more to worry then just the O2 – CO2 mix, but also methane, and many other odd gases that need to be removed or exchanged.

You will need light to grow the algie – and you will need a lot of water, say, 1000L of water per person,

well actually 20L is sufficent, at least for air-supply,

If you mean algae for food, that’s a mildy different topic,

though I’m sure algae-for-food can be grown outside.

and anyone knows that humidity will be a issue in a enclosed space and that much water

In Canada winters are very dry, usually I have to drink lots of water to compensate,

even though I have the aquarium providing humidity it could be more humid.

currently I’m also boiling water with some sensual spices, both for heating and humidity.

you know what, even with all that, my lips are still drier than they could be.

- however for those who are shallow enough to get light, I could see it as a great extender of your air – if your close enough for light,

well there is quite a bit of light likely going through the windows,

but we only need electricity to have the grow-lights going,

I’m using 28 watt LED grow-light and it’s more than enough.

then you can occasionally vent and exchange the air (And you can eat algie). or have enough power to run lights -

sure we could exchange air and go outside.

well If you have power for any lighting at all inside,

then you certainly have power LED grow-lights.

but if your running lights it may be more effective to do what the space station does and produce O2 from water and then clean out the Co2 and other toxins with filters.

space station mainly does that stuff cause they have whoping excesses of money.

Dehumidifiers might be a good way to get some of the moisture out (and provide drinking water) but that is energy intensive.

Really, the ocean is made of water,

as long as you have a dominance of beneficial fungi,

then even if it’s 100% humidity you’ll still be just fine.

Personally I allow rhizopus (edible-bread-mold) to bloom,

nowadays penicilium (toxic-anti-biotic) is a rare sight indeed.

Activated Carbon is a great air filter to remove toxins from the air – as in a cosed loop you will have more to worry then just the O2 – CO2 mix, but also methane, and many other odd gases that need to be removed or exchanged.

yes, activated carbon was something before it became a charred black mass,

what was it? a plant, that is also great at filtering and cleaning all the aftmentioned gasses.

If you have a deep-sand-bed can filter out sulfides, nitrates, and many other things.

fortunately the days are also longer, so I just increased the day-lights for an extra half-hour.

Now it’s only 3 or 4 hours before sunrise and the air is still full of oxygen and has very fresh quality to it.

calm aware desire choice love express intuit move

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Elspru, I was suggesting you use a lab rat in an experiment where you put the aquarium and lab rat in an air tight enclosure such as a Garbage bag or tupperware container. If the rat is still alive in a week, you increase the number of rats until they start suffocating.

Elspru, I was suggesting you use a lab rat in an experiment where you put the aquarium and lab rat in an air tight enclosure such as a Garbage bag or tupperware container. If the rat is still alive in a week, you increase the number of rats until they start suffocating.

It’s not exactly humane

no it’s downright cruel.

I have ethics, unlike the Descartean Scientists.

Countless hours of animal pain and torture, since Descartes claimed they didn’t have souls.

Elspru, I was suggesting you use a lab rat in an experiment where you put the aquarium and lab rat in an air tight enclosure such as a Garbage bag or tupperware container. If the rat is still alive in a week, you increase the number of rats until they start suffocating.

It’s not exactly humane

no it’s downright cruel.

I have ethics, unlike the Descartean Scientists.

Countless hours of animal pain and torture, since Descartes claimed they didn’t have souls.

can you imagine that? Billions of years of evolution, make for a very well refined tool.

If you haven’t yet learned to use it volitionally yet, then I’d suggest meditation.

calm aware desire choice love express intuit move

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Ethics are complicated.

Is it ethical to neglect rigorous quantitative data on a subject matter which will impact life or death situations?

Is it ethical to cut costs on co2 sensors for the same reasons?

What if the co2 sensors are cost prohibitive and the study simply won’t take place unless an alternative is found?

Is it ethical to neglect to conduct the study when every day millions of people kill themselves by the minute to afford a roof over their heads?

You’re right though: so long as there is no concern of toxins, human lungs are an excellent measure of Co2 levels. It’s important to conduct the study under representative conditions while taking measures to ensure safety. Because life and limb are at stake, I’m not willing to make suggestions on the subject, however the most important thing is the immediate access to normal breathable air under emergency conditions. A dead mans switch would even be prudent where something as simple as the relaxation of muscles will result in the assured access to air.

Sorry that I was not clear — I was refering to living underwater with the system, not testing it…

The Biosub had 100L of biocoil, and that produced 10% of his Oxygen needs, so you would need at least 1000L of biocoil to produce enough oxygen to be self-sustaining. Most likely 1200L to give you some leeway, in addition, Carbon dioxide is not the only air-quality concern if you have a closed loop system, as you have other gases, such as methane, that will build up in a closed system, while if you have a imbalance where your producing more Carbon Dioxide then Oxygen the Carbon dioxide will cause you the most trouble (for example, the biosub experiment had to be cut short as there was issues of buildup of Carbon Dioxide even with daily venting of outside air. However even if you solve that issue there is the trace gases which will kill you if you do not remove them (and plant life will not remove such gases)

In closed loop systems there has been two ways to handle this traditionally – A occasional venting of fresh air to put the system back into equal balance, or though the scrubbing of Carbon Dioxide and trace gasses while added Oxygen. Living under-water gives a major advantage as you have a unlimited resource in water, which can provide oxygen though Electrical means (the hydrogen is vented out of the closed loop).

For example, the space station, which does not have unlimited water, collects waste water and cleans some of it, and the rest is made into Oxygen. Filters scrub out the carbon dioxide and the trace gases. For underwater use, a snorkel system provides a simple way to maintain good air. If your looking at a closed system, not only will you have to produce oxygen, but also you will need to remove trace gasses.

As for your experiment, my only concern is that if you do not have it air-tight, you will not get valid results as even the most shut in living residence has a lot of air-transfer.

However in wage-slavery the chains are debts or mortgages, and whips are interest or rent.

You’re right though: so long as there is no concern of toxins, human lungs are an excellent measure of Co2 levels.

can also have small animals such as the prototypical canary if you are really concerned.

fact is many people live on boats with minimal detriment.

ya some people die from CO or carbon-monoxide poisoning,

typically those that use petrochemical-engines, carbon-monoxide detectors are fairly cheap.

however the most important thing is the immediate access to normal breathable air under emergency conditions. A dead mans switch would even be prudent where something as simple as the relaxation of muscles will result in the assured access to air.

Sorry that I was not clear — I was refering to living underwater with the system, not testing it…

The Biosub had 100L of biocoil, and that produced 10% of his Oxygen needs, so you would need at least 1000L of biocoil to produce enough oxygen to be self-sustaining.

Most likely 1200L to give you some leeway, in addition,

Biocoil sounds like some very poor proprietary product.

and you didn’t cite your sources.

In the very first post of this thread,

I have the amount of algae that is required

about 1kg per person, suspended in 20L of liquid.

which could fit in a cubic-foot sized aquarium.

It also cites the source.

Carbon dioxide is not the only air-quality concern if you have a closed loop system, as you have other gases, such as methane, that will build up in a closed system,

Methane is produced by anaerobic decay.

As long as you seperate liquids and solids, only aerobic decay occurs, such as in compost-toilet.

Though you could of course take advantage of anerobic digestion methane in controlled environment,

to heat your water and have a fuel for your stove.

sure if you are collecting any flammable gas, like methane or hydrogen there will be leaks,

fortunately these are lighter-than-air-compounds, so as long as you surface and open your ports occasionally it’ll disipate.

while if you have a imbalance where your producing more Carbon Dioxide then Oxygen the Carbon dioxide will cause you the most trouble (for example, the biosub experiment had to be cut short as there was issues of buildup of Carbon Dioxide even with daily venting of outside air. However even if you solve that issue there is the trace gases which will kill you if you do not remove them (and plant life will not remove such gases)

yes well this “biosub” sounds like it’s some kind of profit-driven experiment to test some of their proprietary “biocoil” contraption.

which as many recent human inventions such as pharmaceuticals are far inferior to those which can easily be acquired from nature.

In closed loop systems there has been two ways to handle this traditionally – A occasional venting of fresh air to put the system back into equal balance, or though the scrubbing of Carbon Dioxide and trace gasses while added Oxygen. Living under-water gives a major advantage as you have a unlimited resource in water, which can provide oxygen though Electrical means (the hydrogen is vented out of the closed loop).

sure you can get oxygen out of electrolysis, it does require quite a bit of energy.

When you combust the hydrogen, you need those oxygen bits back.

unless you exclusively sell the hydrogen rather than use it yourself.

Also the carbon-dioxide would accumulate regardless.

Do you happen to know how many watts are required to generate a suffient amount of oxygen for a person?

For example, the space station, which does not have unlimited water, collects waste water and cleans some of it, and the rest is made into Oxygen. Filters scrub out the carbon dioxide and the trace gases.

we already went over the fact that they have much more money than we do.

also I can imagine not having gravity would make having an aquarium an unusual task, i.e. how would you aerate it?

In any case, with flying saucers can generate our own gravity, and use the same old aquarium system.

I’m sure you know Nasa is just a public front organization.

The vast majority of government technology is top-secret.

There are at least 18 levels of classified above POTUS (president of the united states).

For underwater use, a snorkel system provides a simple way to maintain good air.

snorkel pumps can break,

and air-pumps tend to be noisy.

Though I do agree it’s best to have backup plans.

If your looking at a closed system, not only will you have to produce oxygen, but also you will need to remove trace gasses.

yes, we covered that.

As for your experiment, my only concern is that if you do not have it air-tight, you will not get valid results as even the most shut in living residence has a lot of air-transfer.

In any case the air-quality is much improved over the ambient outside.

removing carbon dioxide and replenishing oxygen in the atmosphere of a nuclear submarine. For the past 2-1/2 years the feasibility of this method has been investigated in the laboratory

…

6200 ml of algal suspension have been evaluated;

….

the oxygen production was 4500 cc per hour

…

The dependability of the algal system in providing a constant supply of oxygen has been assured by this study; also, the volume requirements of the algal system are competitive with existing systems for carbon dioxide removal and oxygen production.